Merge pull request #474 from AutoMaker-Org/feat/dev-server-log-panel

feat: add dev server log panel with real-time streaming

apps/server/src/index.ts

@@ -67,6 +67,7 @@ import { createPipelineRoutes } from './routes/pipeline/index.js';
 import { pipelineService } from './services/pipeline-service.js';
 import { createIdeationRoutes } from './routes/ideation/index.js';
 import { IdeationService } from './services/ideation-service.js';
+import { getDevServerService } from './services/dev-server-service.js';
 
 // Load environment variables
 dotenv.config();
@@ -176,6 +177,10 @@ const codexUsageService = new CodexUsageService(codexAppServerService);
 const mcpTestService = new MCPTestService(settingsService);
 const ideationService = new IdeationService(events, settingsService, featureLoader);
 
+// Initialize DevServerService with event emitter for real-time log streaming
+const devServerService = getDevServerService();
+devServerService.setEventEmitter(events);
+
 // Initialize services
 (async () => {
   await agentService.initialize();

apps/server/src/middleware/validate-paths.ts

@@ -8,12 +8,28 @@ import type { Request, Response, NextFunction } from 'express';
 import { validatePath, PathNotAllowedError } from '@automaker/platform';
 
 /**
- * Creates a middleware that validates specified path parameters in req.body
+ * Helper to get parameter value from request (checks body first, then query)
+ */
+function getParamValue(req: Request, paramName: string): unknown {
+  // Check body first (for POST/PUT/PATCH requests)
+  if (req.body && req.body[paramName] !== undefined) {
+    return req.body[paramName];
+  }
+  // Fall back to query params (for GET requests)
+  if (req.query && req.query[paramName] !== undefined) {
+    return req.query[paramName];
+  }
+  return undefined;
+}
+
+/**
+ * Creates a middleware that validates specified path parameters in req.body or req.query
  * @param paramNames - Names of parameters to validate (e.g., 'projectPath', 'worktreePath')
  * @example
  * router.post('/create', validatePathParams('projectPath'), handler);
  * router.post('/delete', validatePathParams('projectPath', 'worktreePath'), handler);
  * router.post('/send', validatePathParams('workingDirectory?', 'imagePaths[]'), handler);
+ * router.get('/logs', validatePathParams('worktreePath'), handler); // Works with query params too
  *
  * Special syntax:
  * - 'paramName?' - Optional parameter (only validated if present)
@@ -26,8 +42,8 @@ export function validatePathParams(...paramNames: string[]) {
         // Handle optional parameters (paramName?)
         if (paramName.endsWith('?')) {
           const actualName = paramName.slice(0, -1);
-          const value = req.body[actualName];
-          if (value) {
+          const value = getParamValue(req, actualName);
+          if (value && typeof value === 'string') {
             validatePath(value);
           }
           continue;
@@ -36,18 +52,20 @@ export function validatePathParams(...paramNames: string[]) {
         // Handle array parameters (paramName[])
         if (paramName.endsWith('[]')) {
           const actualName = paramName.slice(0, -2);
-          const values = req.body[actualName];
+          const values = getParamValue(req, actualName);
           if (Array.isArray(values) && values.length > 0) {
             for (const value of values) {
-              validatePath(value);
+              if (typeof value === 'string') {
+                validatePath(value);
+              }
             }
           }
           continue;
         }
 
         // Handle regular parameters
-        const value = req.body[paramName];
-        if (value) {
+        const value = getParamValue(req, paramName);
+        if (value && typeof value === 'string') {
           validatePath(value);
         }
       }

apps/server/src/routes/worktree/index.ts

@@ -34,6 +34,7 @@ import { createMigrateHandler } from './routes/migrate.js';
 import { createStartDevHandler } from './routes/start-dev.js';
 import { createStopDevHandler } from './routes/stop-dev.js';
 import { createListDevServersHandler } from './routes/list-dev-servers.js';
+import { createGetDevServerLogsHandler } from './routes/dev-server-logs.js';
 import {
   createGetInitScriptHandler,
   createPutInitScriptHandler,
@@ -108,6 +109,11 @@ export function createWorktreeRoutes(
   );
   router.post('/stop-dev', createStopDevHandler());
   router.post('/list-dev-servers', createListDevServersHandler());
+  router.get(
+    '/dev-server-logs',
+    validatePathParams('worktreePath'),
+    createGetDevServerLogsHandler()
+  );
 
   // Init script routes
   router.get('/init-script', createGetInitScriptHandler());

apps/server/src/routes/worktree/routes/dev-server-logs.ts

@@ -0,0 +1,52 @@
+/**
+ * GET /dev-server-logs endpoint - Get buffered logs for a worktree's dev server
+ *
+ * Returns the scrollback buffer containing historical log output for a running
+ * dev server. Used by clients to populate the log panel on initial connection
+ * before subscribing to real-time updates via WebSocket.
+ */
+
+import type { Request, Response } from 'express';
+import { getDevServerService } from '../../../services/dev-server-service.js';
+import { getErrorMessage, logError } from '../common.js';
+
+export function createGetDevServerLogsHandler() {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const { worktreePath } = req.query as {
+        worktreePath?: string;
+      };
+
+      if (!worktreePath) {
+        res.status(400).json({
+          success: false,
+          error: 'worktreePath query parameter is required',
+        });
+        return;
+      }
+
+      const devServerService = getDevServerService();
+      const result = devServerService.getServerLogs(worktreePath);
+
+      if (result.success && result.result) {
+        res.json({
+          success: true,
+          result: {
+            worktreePath: result.result.worktreePath,
+            port: result.result.port,
+            logs: result.result.logs,
+            startedAt: result.result.startedAt,
+          },
+        });
+      } else {
+        res.status(404).json({
+          success: false,
+          error: result.error || 'Failed to get dev server logs',
+        });
+      }
+    } catch (error) {
+      logError(error, 'Get dev server logs failed');
+      res.status(500).json({ success: false, error: getErrorMessage(error) });
+    }
+  };
+}

apps/server/src/services/dev-server-service.ts

@@ -12,24 +12,123 @@ import * as secureFs from '../lib/secure-fs.js';
 import path from 'path';
 import net from 'net';
 import { createLogger } from '@automaker/utils';
+import type { EventEmitter } from '../lib/events.js';
 
 const logger = createLogger('DevServerService');
 
+// Maximum scrollback buffer size (characters) - matches TerminalService pattern
+const MAX_SCROLLBACK_SIZE = 50000; // ~50KB per dev server
+
+// Throttle output to prevent overwhelming WebSocket under heavy load
+const OUTPUT_THROTTLE_MS = 4; // ~250fps max update rate for responsive feedback
+const OUTPUT_BATCH_SIZE = 4096; // Smaller batches for lower latency
+
 export interface DevServerInfo {
   worktreePath: string;
   port: number;
   url: string;
   process: ChildProcess | null;
   startedAt: Date;
+  // Scrollback buffer for log history (replay on reconnect)
+  scrollbackBuffer: string;
+  // Pending output to be flushed to subscribers
+  outputBuffer: string;
+  // Throttle timer for batching output
+  flushTimeout: NodeJS.Timeout | null;
+  // Flag to indicate server is stopping (prevents output after stop)
+  stopping: boolean;
 }
 
 // Port allocation starts at 3001 to avoid conflicts with common dev ports
 const BASE_PORT = 3001;
 const MAX_PORT = 3099; // Safety limit
 
+// Common livereload ports that may need cleanup when stopping dev servers
+const LIVERELOAD_PORTS = [35729, 35730, 35731] as const;
+
 class DevServerService {
   private runningServers: Map<string, DevServerInfo> = new Map();
   private allocatedPorts: Set<number> = new Set();
+  private emitter: EventEmitter | null = null;
+
+  /**
+   * Set the event emitter for streaming log events
+   * Called during service initialization with the global event emitter
+   */
+  setEventEmitter(emitter: EventEmitter): void {
+    this.emitter = emitter;
+  }
+
+  /**
+   * Append data to scrollback buffer with size limit enforcement
+   * Evicts oldest data when buffer exceeds MAX_SCROLLBACK_SIZE
+   */
+  private appendToScrollback(server: DevServerInfo, data: string): void {
+    server.scrollbackBuffer += data;
+    if (server.scrollbackBuffer.length > MAX_SCROLLBACK_SIZE) {
+      server.scrollbackBuffer = server.scrollbackBuffer.slice(-MAX_SCROLLBACK_SIZE);
+    }
+  }
+
+  /**
+   * Flush buffered output to WebSocket subscribers
+   * Sends batched output to prevent overwhelming clients under heavy load
+   */
+  private flushOutput(server: DevServerInfo): void {
+    // Skip flush if server is stopping or buffer is empty
+    if (server.stopping || server.outputBuffer.length === 0) {
+      server.flushTimeout = null;
+      return;
+    }
+
+    let dataToSend = server.outputBuffer;
+    if (dataToSend.length > OUTPUT_BATCH_SIZE) {
+      // Send in batches if buffer is large
+      dataToSend = server.outputBuffer.slice(0, OUTPUT_BATCH_SIZE);
+      server.outputBuffer = server.outputBuffer.slice(OUTPUT_BATCH_SIZE);
+      // Schedule another flush for remaining data
+      server.flushTimeout = setTimeout(() => this.flushOutput(server), OUTPUT_THROTTLE_MS);
+    } else {
+      server.outputBuffer = '';
+      server.flushTimeout = null;
+    }
+
+    // Emit output event for WebSocket streaming
+    if (this.emitter) {
+      this.emitter.emit('dev-server:output', {
+        worktreePath: server.worktreePath,
+        content: dataToSend,
+        timestamp: new Date().toISOString(),
+      });
+    }
+  }
+
+  /**
+   * Handle incoming stdout/stderr data from dev server process
+   * Buffers data for scrollback replay and schedules throttled emission
+   */
+  private handleProcessOutput(server: DevServerInfo, data: Buffer): void {
+    // Skip output if server is stopping
+    if (server.stopping) {
+      return;
+    }
+
+    const content = data.toString();
+
+    // Append to scrollback buffer for replay on reconnect
+    this.appendToScrollback(server, content);
+
+    // Buffer output for throttled live delivery
+    server.outputBuffer += content;
+
+    // Schedule flush if not already scheduled
+    if (!server.flushTimeout) {
+      server.flushTimeout = setTimeout(() => this.flushOutput(server), OUTPUT_THROTTLE_MS);
+    }
+
+    // Also log for debugging (existing behavior)
+    logger.debug(`[Port${server.port}] ${content.trim()}`);
+  }
 
   /**
    * Check if a port is available (not in use by system or by us)
@@ -244,10 +343,9 @@ class DevServerService {
     // Reserve the port (port was already force-killed in findAvailablePort)
     this.allocatedPorts.add(port);
 
-    // Also kill common related ports (livereload uses 35729 by default)
+    // Also kill common related ports (livereload, etc.)
     // Some dev servers use fixed ports for HMR/livereload regardless of main port
-    const commonRelatedPorts = [35729, 35730, 35731];
-    for (const relatedPort of commonRelatedPorts) {
+    for (const relatedPort of LIVERELOAD_PORTS) {
       this.killProcessOnPort(relatedPort);
     }
 
@@ -259,9 +357,14 @@ class DevServerService {
     logger.debug(`Command: ${devCommand.cmd} ${devCommand.args.join(' ')} with PORT=${port}`);
 
     // Spawn the dev process with PORT environment variable
+    // FORCE_COLOR enables colored output even when not running in a TTY
     const env = {
       ...process.env,
       PORT: String(port),
+      FORCE_COLOR: '1',
+      // Some tools use these additional env vars for color detection
+      COLORTERM: 'truecolor',
+      TERM: 'xterm-256color',
     };
 
     const devProcess = spawn(devCommand.cmd, devCommand.args, {
@@ -274,32 +377,66 @@ class DevServerService {
     // Track if process failed early using object to work around TypeScript narrowing
     const status = { error: null as string | null, exited: false };
 
-    // Log output for debugging
+    // Create server info early so we can reference it in handlers
+    // We'll add it to runningServers after verifying the process started successfully
+    const serverInfo: DevServerInfo = {
+      worktreePath,
+      port,
+      url: `http://localhost:${port}`,
+      process: devProcess,
+      startedAt: new Date(),
+      scrollbackBuffer: '',
+      outputBuffer: '',
+      flushTimeout: null,
+      stopping: false,
+    };
+
+    // Capture stdout with buffer management and event emission
     if (devProcess.stdout) {
       devProcess.stdout.on('data', (data: Buffer) => {
-        logger.debug(`[Port${port}] ${data.toString().trim()}`);
+        this.handleProcessOutput(serverInfo, data);
       });
     }
 
+    // Capture stderr with buffer management and event emission
     if (devProcess.stderr) {
       devProcess.stderr.on('data', (data: Buffer) => {
-        const msg = data.toString().trim();
-        logger.debug(`[Port${port}] ${msg}`);
+        this.handleProcessOutput(serverInfo, data);
       });
     }
 
+    // Helper to clean up resources and emit stop event
+    const cleanupAndEmitStop = (exitCode: number | null, errorMessage?: string) => {
+      if (serverInfo.flushTimeout) {
+        clearTimeout(serverInfo.flushTimeout);
+        serverInfo.flushTimeout = null;
+      }
+
+      // Emit stopped event (only if not already stopping - prevents duplicate events)
+      if (this.emitter && !serverInfo.stopping) {
+        this.emitter.emit('dev-server:stopped', {
+          worktreePath,
+          port,
+          exitCode,
+          error: errorMessage,
+          timestamp: new Date().toISOString(),
+        });
+      }
+
+      this.allocatedPorts.delete(port);
+      this.runningServers.delete(worktreePath);
+    };
+
     devProcess.on('error', (error) => {
       logger.error(`Process error:`, error);
       status.error = error.message;
-      this.allocatedPorts.delete(port);
-      this.runningServers.delete(worktreePath);
+      cleanupAndEmitStop(null, error.message);
     });
 
     devProcess.on('exit', (code) => {
       logger.info(`Process for ${worktreePath} exited with code ${code}`);
       status.exited = true;
-      this.allocatedPorts.delete(port);
-      this.runningServers.delete(worktreePath);
+      cleanupAndEmitStop(code);
     });
 
     // Wait a moment to see if the process fails immediately
@@ -319,16 +456,19 @@ class DevServerService {
       };
     }
 
-    const serverInfo: DevServerInfo = {
-      worktreePath,
-      port,
-      url: `http://localhost:${port}`,
-      process: devProcess,
-      startedAt: new Date(),
-    };
-
+    // Server started successfully - add to running servers map
     this.runningServers.set(worktreePath, serverInfo);
 
+    // Emit started event for WebSocket subscribers
+    if (this.emitter) {
+      this.emitter.emit('dev-server:started', {
+        worktreePath,
+        port,
+        url: serverInfo.url,
+        timestamp: new Date().toISOString(),
+      });
+    }
+
     return {
       success: true,
       result: {
@@ -365,6 +505,28 @@ class DevServerService {
 
     logger.info(`Stopping dev server for ${worktreePath}`);
 
+    // Mark as stopping to prevent further output events
+    server.stopping = true;
+
+    // Clean up flush timeout to prevent memory leaks
+    if (server.flushTimeout) {
+      clearTimeout(server.flushTimeout);
+      server.flushTimeout = null;
+    }
+
+    // Clear any pending output buffer
+    server.outputBuffer = '';
+
+    // Emit stopped event immediately so UI updates right away
+    if (this.emitter) {
+      this.emitter.emit('dev-server:stopped', {
+        worktreePath,
+        port: server.port,
+        exitCode: null, // Will be populated by exit handler if process exits normally
+        timestamp: new Date().toISOString(),
+      });
+    }
+
     // Kill the process
     if (server.process && !server.process.killed) {
       server.process.kill('SIGTERM');
@@ -422,6 +584,41 @@ class DevServerService {
     return this.runningServers.get(worktreePath);
   }
 
+  /**
+   * Get buffered logs for a worktree's dev server
+   * Returns the scrollback buffer containing historical log output
+   * Used by the API to serve logs to clients on initial connection
+   */
+  getServerLogs(worktreePath: string): {
+    success: boolean;
+    result?: {
+      worktreePath: string;
+      port: number;
+      logs: string;
+      startedAt: string;
+    };
+    error?: string;
+  } {
+    const server = this.runningServers.get(worktreePath);
+
+    if (!server) {
+      return {
+        success: false,
+        error: `No dev server running for worktree: ${worktreePath}`,
+      };
+    }
+
+    return {
+      success: true,
+      result: {
+        worktreePath: server.worktreePath,
+        port: server.port,
+        logs: server.scrollbackBuffer,
+        startedAt: server.startedAt.toISOString(),
+      },
+    };
+  }
+
   /**
    * Get all allocated ports
    */

apps/ui/src/components/ui/xterm-log-viewer.tsx

@@ -0,0 +1,300 @@
+import { useEffect, useRef, useCallback, useState, forwardRef, useImperativeHandle } from 'react';
+import { useAppStore } from '@/store/app-store';
+import { getTerminalTheme, DEFAULT_TERMINAL_FONT } from '@/config/terminal-themes';
+
+// Types for dynamically imported xterm modules
+type XTerminal = InstanceType<typeof import('@xterm/xterm').Terminal>;
+type XFitAddon = InstanceType<typeof import('@xterm/addon-fit').FitAddon>;
+
+export interface XtermLogViewerRef {
+  /** Append content to the log viewer */
+  append: (content: string) => void;
+  /** Clear all content */
+  clear: () => void;
+  /** Scroll to the bottom */
+  scrollToBottom: () => void;
+  /** Write content (replaces all content) */
+  write: (content: string) => void;
+}
+
+export interface XtermLogViewerProps {
+  /** Initial content to display */
+  initialContent?: string;
+  /** Font size in pixels (default: 13) */
+  fontSize?: number;
+  /** Whether to auto-scroll to bottom when new content is added (default: true) */
+  autoScroll?: boolean;
+  /** Custom class name for the container */
+  className?: string;
+  /** Minimum height for the container */
+  minHeight?: number;
+  /** Callback when user scrolls away from bottom */
+  onScrollAwayFromBottom?: () => void;
+  /** Callback when user scrolls to bottom */
+  onScrollToBottom?: () => void;
+}
+
+/**
+ * A read-only terminal log viewer using xterm.js for perfect ANSI color rendering.
+ * Use this component when you need to display terminal output with ANSI escape codes.
+ */
+export const XtermLogViewer = forwardRef<XtermLogViewerRef, XtermLogViewerProps>(
+  (
+    {
+      initialContent,
+      fontSize = 13,
+      autoScroll = true,
+      className,
+      minHeight = 300,
+      onScrollAwayFromBottom,
+      onScrollToBottom,
+    },
+    ref
+  ) => {
+    const containerRef = useRef<HTMLDivElement>(null);
+    const xtermRef = useRef<XTerminal | null>(null);
+    const fitAddonRef = useRef<XFitAddon | null>(null);
+    const [isReady, setIsReady] = useState(false);
+    const autoScrollRef = useRef(autoScroll);
+    const pendingContentRef = useRef<string[]>([]);
+
+    // Get theme from store
+    const getEffectiveTheme = useAppStore((state) => state.getEffectiveTheme);
+    const effectiveTheme = getEffectiveTheme();
+
+    // Track system dark mode for "system" theme
+    const [systemIsDark, setSystemIsDark] = useState(() => {
+      if (typeof window !== 'undefined') {
+        return window.matchMedia('(prefers-color-scheme: dark)').matches;
+      }
+      return true;
+    });
+
+    useEffect(() => {
+      const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
+      const handleChange = (e: MediaQueryListEvent) => setSystemIsDark(e.matches);
+      mediaQuery.addEventListener('change', handleChange);
+      return () => mediaQuery.removeEventListener('change', handleChange);
+    }, []);
+
+    const resolvedTheme =
+      effectiveTheme === 'system' ? (systemIsDark ? 'dark' : 'light') : effectiveTheme;
+
+    // Update autoScroll ref when prop changes
+    useEffect(() => {
+      autoScrollRef.current = autoScroll;
+    }, [autoScroll]);
+
+    // Initialize xterm
+    useEffect(() => {
+      if (!containerRef.current) return;
+
+      let mounted = true;
+
+      const initTerminal = async () => {
+        const [{ Terminal }, { FitAddon }] = await Promise.all([
+          import('@xterm/xterm'),
+          import('@xterm/addon-fit'),
+        ]);
+        await import('@xterm/xterm/css/xterm.css');
+
+        if (!mounted || !containerRef.current) return;
+
+        const terminalTheme = getTerminalTheme(resolvedTheme);
+
+        const terminal = new Terminal({
+          cursorBlink: false,
+          cursorStyle: 'underline',
+          cursorInactiveStyle: 'none',
+          fontSize,
+          fontFamily: DEFAULT_TERMINAL_FONT,
+          lineHeight: 1.2,
+          theme: terminalTheme,
+          disableStdin: true, // Read-only mode
+          scrollback: 10000,
+          convertEol: true,
+        });
+
+        const fitAddon = new FitAddon();
+        terminal.loadAddon(fitAddon);
+
+        terminal.open(containerRef.current);
+
+        // Try to load WebGL addon for better performance
+        try {
+          const { WebglAddon } = await import('@xterm/addon-webgl');
+          const webglAddon = new WebglAddon();
+          webglAddon.onContextLoss(() => webglAddon.dispose());
+          terminal.loadAddon(webglAddon);
+        } catch {
+          // WebGL not available, continue with canvas renderer
+        }
+
+        // Wait for layout to stabilize then fit
+        requestAnimationFrame(() => {
+          if (mounted && containerRef.current) {
+            try {
+              fitAddon.fit();
+            } catch {
+              // Ignore fit errors during initialization
+            }
+          }
+        });
+
+        xtermRef.current = terminal;
+        fitAddonRef.current = fitAddon;
+        setIsReady(true);
+
+        // Write initial content if provided
+        if (initialContent) {
+          terminal.write(initialContent);
+        }
+
+        // Write any pending content that was queued before terminal was ready
+        if (pendingContentRef.current.length > 0) {
+          pendingContentRef.current.forEach((content) => terminal.write(content));
+          pendingContentRef.current = [];
+        }
+      };
+
+      initTerminal();
+
+      return () => {
+        mounted = false;
+        if (xtermRef.current) {
+          xtermRef.current.dispose();
+          xtermRef.current = null;
+        }
+        fitAddonRef.current = null;
+        setIsReady(false);
+      };
+    }, []); // Only run once on mount
+
+    // Update theme when it changes
+    useEffect(() => {
+      if (xtermRef.current && isReady) {
+        const terminalTheme = getTerminalTheme(resolvedTheme);
+        xtermRef.current.options.theme = terminalTheme;
+      }
+    }, [resolvedTheme, isReady]);
+
+    // Update font size when it changes
+    useEffect(() => {
+      if (xtermRef.current && isReady) {
+        xtermRef.current.options.fontSize = fontSize;
+        fitAddonRef.current?.fit();
+      }
+    }, [fontSize, isReady]);
+
+    // Handle resize
+    useEffect(() => {
+      if (!containerRef.current || !isReady) return;
+
+      const handleResize = () => {
+        if (fitAddonRef.current && containerRef.current) {
+          const rect = containerRef.current.getBoundingClientRect();
+          if (rect.width > 0 && rect.height > 0) {
+            try {
+              fitAddonRef.current.fit();
+            } catch {
+              // Ignore fit errors
+            }
+          }
+        }
+      };
+
+      const resizeObserver = new ResizeObserver(handleResize);
+      resizeObserver.observe(containerRef.current);
+      window.addEventListener('resize', handleResize);
+
+      return () => {
+        resizeObserver.disconnect();
+        window.removeEventListener('resize', handleResize);
+      };
+    }, [isReady]);
+
+    // Monitor scroll position
+    useEffect(() => {
+      if (!isReady || !containerRef.current) return;
+
+      const viewport = containerRef.current.querySelector('.xterm-viewport') as HTMLElement | null;
+      if (!viewport) return;
+
+      const checkScroll = () => {
+        const { scrollTop, scrollHeight, clientHeight } = viewport;
+        const isAtBottom = scrollHeight - scrollTop - clientHeight <= 10;
+
+        if (isAtBottom) {
+          autoScrollRef.current = true;
+          onScrollToBottom?.();
+        } else {
+          autoScrollRef.current = false;
+          onScrollAwayFromBottom?.();
+        }
+      };
+
+      viewport.addEventListener('scroll', checkScroll, { passive: true });
+      return () => viewport.removeEventListener('scroll', checkScroll);
+    }, [isReady, onScrollAwayFromBottom, onScrollToBottom]);
+
+    // Expose methods via ref
+    const append = useCallback((content: string) => {
+      if (xtermRef.current) {
+        xtermRef.current.write(content);
+        if (autoScrollRef.current) {
+          xtermRef.current.scrollToBottom();
+        }
+      } else {
+        // Queue content if terminal isn't ready yet
+        pendingContentRef.current.push(content);
+      }
+    }, []);
+
+    const clear = useCallback(() => {
+      if (xtermRef.current) {
+        xtermRef.current.clear();
+      }
+    }, []);
+
+    const scrollToBottom = useCallback(() => {
+      if (xtermRef.current) {
+        xtermRef.current.scrollToBottom();
+        autoScrollRef.current = true;
+      }
+    }, []);
+
+    const write = useCallback((content: string) => {
+      if (xtermRef.current) {
+        xtermRef.current.reset();
+        xtermRef.current.write(content);
+        if (autoScrollRef.current) {
+          xtermRef.current.scrollToBottom();
+        }
+      } else {
+        pendingContentRef.current = [content];
+      }
+    }, []);
+
+    useImperativeHandle(ref, () => ({
+      append,
+      clear,
+      scrollToBottom,
+      write,
+    }));
+
+    const terminalTheme = getTerminalTheme(resolvedTheme);
+
+    return (
+      <div
+        ref={containerRef}
+        className={className}
+        style={{
+          minHeight,
+          backgroundColor: terminalTheme.background,
+        }}
+      />
+    );
+  }
+);
+
+XtermLogViewer.displayName = 'XtermLogViewer';

apps/ui/src/components/views/board-view/worktree-panel/components/dev-server-logs-panel.tsx

@@ -0,0 +1,289 @@
+import { useEffect, useRef, useCallback, useState } from 'react';
+import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/ui/dialog';
+import { Button } from '@/components/ui/button';
+import {
+  Loader2,
+  Terminal,
+  ArrowDown,
+  ExternalLink,
+  Square,
+  RefreshCw,
+  AlertCircle,
+  Clock,
+  GitBranch,
+} from 'lucide-react';
+import { cn } from '@/lib/utils';
+import { XtermLogViewer, type XtermLogViewerRef } from '@/components/ui/xterm-log-viewer';
+import { useDevServerLogs } from '../hooks/use-dev-server-logs';
+import type { WorktreeInfo } from '../types';
+
+interface DevServerLogsPanelProps {
+  /** Whether the panel is open */
+  open: boolean;
+  /** Callback when the panel is closed */
+  onClose: () => void;
+  /** The worktree to show logs for */
+  worktree: WorktreeInfo | null;
+  /** Callback to stop the dev server */
+  onStopDevServer?: (worktree: WorktreeInfo) => void;
+  /** Callback to open the dev server URL in browser */
+  onOpenDevServerUrl?: (worktree: WorktreeInfo) => void;
+}
+
+/**
+ * Panel component for displaying dev server logs with ANSI color rendering
+ * and auto-scroll functionality.
+ *
+ * Features:
+ * - Real-time log streaming via WebSocket
+ * - Full ANSI color code rendering via xterm.js
+ * - Auto-scroll to bottom (can be paused by scrolling up)
+ * - Server status indicators
+ * - Quick actions (stop server, open in browser)
+ */
+export function DevServerLogsPanel({
+  open,
+  onClose,
+  worktree,
+  onStopDevServer,
+  onOpenDevServerUrl,
+}: DevServerLogsPanelProps) {
+  const xtermRef = useRef<XtermLogViewerRef>(null);
+  const [autoScrollEnabled, setAutoScrollEnabled] = useState(true);
+  const lastLogsLengthRef = useRef(0);
+  const lastWorktreePathRef = useRef<string | null>(null);
+
+  const {
+    logs,
+    isRunning,
+    isLoading,
+    error,
+    port,
+    url,
+    startedAt,
+    exitCode,
+    serverError,
+    fetchLogs,
+  } = useDevServerLogs({
+    worktreePath: open ? (worktree?.path ?? null) : null,
+    autoSubscribe: open,
+  });
+
+  // Write logs to xterm when they change
+  useEffect(() => {
+    if (!xtermRef.current || !logs) return;
+
+    // If worktree changed, reset the terminal and write all content
+    if (lastWorktreePathRef.current !== worktree?.path) {
+      lastWorktreePathRef.current = worktree?.path ?? null;
+      lastLogsLengthRef.current = 0;
+      xtermRef.current.write(logs);
+      lastLogsLengthRef.current = logs.length;
+      return;
+    }
+
+    // If logs got shorter (e.g., cleared), rewrite all
+    if (logs.length < lastLogsLengthRef.current) {
+      xtermRef.current.write(logs);
+      lastLogsLengthRef.current = logs.length;
+      return;
+    }
+
+    // Append only the new content
+    if (logs.length > lastLogsLengthRef.current) {
+      const newContent = logs.slice(lastLogsLengthRef.current);
+      xtermRef.current.append(newContent);
+      lastLogsLengthRef.current = logs.length;
+    }
+  }, [logs, worktree?.path]);
+
+  // Reset when panel opens with a new worktree
+  useEffect(() => {
+    if (open) {
+      setAutoScrollEnabled(true);
+      if (worktree?.path !== lastWorktreePathRef.current) {
+        lastLogsLengthRef.current = 0;
+      }
+    }
+  }, [open, worktree?.path]);
+
+  // Scroll to bottom handler
+  const scrollToBottom = useCallback(() => {
+    xtermRef.current?.scrollToBottom();
+    setAutoScrollEnabled(true);
+  }, []);
+
+  // Format the started time
+  const formatStartedAt = useCallback((timestamp: string | null) => {
+    if (!timestamp) return null;
+    try {
+      const date = new Date(timestamp);
+      return date.toLocaleTimeString();
+    } catch {
+      return null;
+    }
+  }, []);
+
+  if (!worktree) return null;
+
+  const formattedStartTime = formatStartedAt(startedAt);
+  const lineCount = logs ? logs.split('\n').length : 0;
+
+  return (
+    <Dialog open={open} onOpenChange={(isOpen) => !isOpen && onClose()}>
+      <DialogContent
+        className="w-[70vw] max-w-[900px] max-h-[85vh] flex flex-col gap-0 p-0 overflow-hidden"
+        data-testid="dev-server-logs-panel"
+      >
+        {/* Compact Header */}
+        <DialogHeader className="shrink-0 px-4 py-3 border-b border-border/50">
+          <div className="flex items-center justify-between">
+            <DialogTitle className="flex items-center gap-2 text-base">
+              <Terminal className="w-4 h-4 text-primary" />
+              <span>Dev Server</span>
+              {isRunning ? (
+                <span className="inline-flex items-center gap-1.5 px-2 py-0.5 rounded-full bg-green-500/10 text-green-500 text-xs font-medium">
+                  <span className="w-1.5 h-1.5 rounded-full bg-green-500 animate-pulse" />
+                  Running
+                </span>
+              ) : exitCode !== null ? (
+                <span className="inline-flex items-center gap-1.5 px-2 py-0.5 rounded-full bg-red-500/10 text-red-500 text-xs font-medium">
+                  <AlertCircle className="w-3 h-3" />
+                  Stopped ({exitCode})
+                </span>
+              ) : null}
+            </DialogTitle>
+            <div className="flex items-center gap-1.5">
+              {isRunning && url && onOpenDevServerUrl && (
+                <Button
+                  variant="ghost"
+                  size="sm"
+                  className="h-7 px-2.5 text-xs"
+                  onClick={() => onOpenDevServerUrl(worktree)}
+                >
+                  <ExternalLink className="w-3.5 h-3.5 mr-1.5" />
+                  Open
+                </Button>
+              )}
+              {isRunning && onStopDevServer && (
+                <Button
+                  variant="ghost"
+                  size="sm"
+                  className="h-7 px-2.5 text-xs text-destructive hover:text-destructive hover:bg-destructive/10"
+                  onClick={() => onStopDevServer(worktree)}
+                >
+                  <Square className="w-3 h-3 mr-1.5 fill-current" />
+                  Stop
+                </Button>
+              )}
+              <Button
+                variant="ghost"
+                size="sm"
+                className="h-7 w-7 p-0"
+                onClick={() => fetchLogs()}
+                title="Refresh logs"
+              >
+                <RefreshCw className={cn('w-3.5 h-3.5', isLoading && 'animate-spin')} />
+              </Button>
+            </div>
+          </div>
+
+          {/* Info bar - more compact */}
+          <div className="flex items-center gap-3 mt-2 text-xs text-muted-foreground">
+            <span className="inline-flex items-center gap-1.5">
+              <GitBranch className="w-3 h-3" />
+              <span className="font-medium text-foreground/80">{worktree.branch}</span>
+            </span>
+            {port && (
+              <span className="inline-flex items-center gap-1.5">
+                <span className="text-muted-foreground/60">Port</span>
+                <span className="font-mono text-primary">{port}</span>
+              </span>
+            )}
+            {formattedStartTime && (
+              <span className="inline-flex items-center gap-1.5">
+                <Clock className="w-3 h-3" />
+                {formattedStartTime}
+              </span>
+            )}
+          </div>
+        </DialogHeader>
+
+        {/* Error displays - inline */}
+        {(error || serverError) && (
+          <div className="shrink-0 px-4 py-2 bg-destructive/5 border-b border-destructive/20">
+            {error && (
+              <div className="flex items-center gap-2 text-xs text-destructive">
+                <AlertCircle className="w-3.5 h-3.5 shrink-0" />
+                <span>{error}</span>
+              </div>
+            )}
+            {serverError && (
+              <div className="flex items-center gap-2 text-xs text-destructive">
+                <AlertCircle className="w-3.5 h-3.5 shrink-0" />
+                <span>Server error: {serverError}</span>
+              </div>
+            )}
+          </div>
+        )}
+
+        {/* Log content area - fills remaining space */}
+        <div
+          className="flex-1 min-h-0 overflow-hidden bg-zinc-950"
+          data-testid="dev-server-logs-content"
+        >
+          {isLoading && !logs ? (
+            <div className="flex items-center justify-center h-full min-h-[300px] text-muted-foreground">
+              <Loader2 className="w-5 h-5 animate-spin mr-2" />
+              <span className="text-sm">Loading logs...</span>
+            </div>
+          ) : !logs && !isRunning ? (
+            <div className="flex flex-col items-center justify-center h-full min-h-[300px] text-muted-foreground p-8">
+              <Terminal className="w-10 h-10 mb-3 opacity-20" />
+              <p className="text-sm">No dev server running</p>
+              <p className="text-xs mt-1 opacity-60">Start a dev server to see logs here</p>
+            </div>
+          ) : !logs ? (
+            <div className="flex flex-col items-center justify-center h-full min-h-[300px] text-muted-foreground p-8">
+              <div className="w-8 h-8 mb-3 rounded-full border-2 border-muted-foreground/20 border-t-muted-foreground/60 animate-spin" />
+              <p className="text-sm">Waiting for output...</p>
+              <p className="text-xs mt-1 opacity-60">
+                Logs will appear as the server generates output
+              </p>
+            </div>
+          ) : (
+            <XtermLogViewer
+              ref={xtermRef}
+              className="h-full"
+              minHeight={280}
+              fontSize={13}
+              autoScroll={autoScrollEnabled}
+              onScrollAwayFromBottom={() => setAutoScrollEnabled(false)}
+              onScrollToBottom={() => setAutoScrollEnabled(true)}
+            />
+          )}
+        </div>
+
+        {/* Footer status bar */}
+        <div className="shrink-0 flex items-center justify-between px-4 py-2 bg-muted/30 border-t border-border/50 text-xs text-muted-foreground">
+          <span className="font-mono">{lineCount > 0 ? `${lineCount} lines` : 'No output'}</span>
+          {!autoScrollEnabled && logs && (
+            <button
+              onClick={scrollToBottom}
+              className="inline-flex items-center gap-1.5 px-2 py-1 rounded hover:bg-muted transition-colors text-primary"
+            >
+              <ArrowDown className="w-3 h-3" />
+              Scroll to bottom
+            </button>
+          )}
+          {autoScrollEnabled && logs && (
+            <span className="inline-flex items-center gap-1.5 opacity-60">
+              <ArrowDown className="w-3 h-3" />
+              Auto-scroll
+            </span>
+          )}
+        </div>
+      </DialogContent>
+    </Dialog>
+  );
+}

apps/ui/src/components/views/board-view/worktree-panel/components/index.ts

@@ -1,4 +1,5 @@
 export { BranchSwitchDropdown } from './branch-switch-dropdown';
+export { DevServerLogsPanel } from './dev-server-logs-panel';
 export { WorktreeActionsDropdown } from './worktree-actions-dropdown';
 export { WorktreeMobileDropdown } from './worktree-mobile-dropdown';
 export { WorktreeTab } from './worktree-tab';

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx

@@ -25,6 +25,7 @@ import {
   AlertCircle,
   RefreshCw,
   Copy,
+  ScrollText,
 } from 'lucide-react';
 import { toast } from 'sonner';
 import { cn } from '@/lib/utils';
@@ -58,6 +59,7 @@ interface WorktreeActionsDropdownProps {
   onStartDevServer: (worktree: WorktreeInfo) => void;
   onStopDevServer: (worktree: WorktreeInfo) => void;
   onOpenDevServerUrl: (worktree: WorktreeInfo) => void;
+  onViewDevServerLogs: (worktree: WorktreeInfo) => void;
   onRunInitScript: (worktree: WorktreeInfo) => void;
   hasInitScript: boolean;
 }
@@ -86,6 +88,7 @@ export function WorktreeActionsDropdown({
   onStartDevServer,
   onStopDevServer,
   onOpenDevServerUrl,
+  onViewDevServerLogs,
   onRunInitScript,
   hasInitScript,
 }: WorktreeActionsDropdownProps) {
@@ -156,6 +159,10 @@ export function WorktreeActionsDropdown({
               <Globe className="w-3.5 h-3.5 mr-2" aria-hidden="true" />
               Open in Browser
             </DropdownMenuItem>
+            <DropdownMenuItem onClick={() => onViewDevServerLogs(worktree)} className="text-xs">
+              <ScrollText className="w-3.5 h-3.5 mr-2" />
+              View Logs
+            </DropdownMenuItem>
             <DropdownMenuItem
               onClick={() => onStopDevServer(worktree)}
               className="text-xs text-destructive focus:text-destructive"

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx

@@ -1,4 +1,4 @@
-// @ts-nocheck
+import type { JSX } from 'react';
 import { Button } from '@/components/ui/button';
 import { RefreshCw, Globe, Loader2, CircleDot, GitPullRequest } from 'lucide-react';
 import { cn } from '@/lib/utils';
@@ -45,6 +45,7 @@ interface WorktreeTabProps {
   onStartDevServer: (worktree: WorktreeInfo) => void;
   onStopDevServer: (worktree: WorktreeInfo) => void;
   onOpenDevServerUrl: (worktree: WorktreeInfo) => void;
+  onViewDevServerLogs: (worktree: WorktreeInfo) => void;
   onRunInitScript: (worktree: WorktreeInfo) => void;
   hasInitScript: boolean;
 }
@@ -87,6 +88,7 @@ export function WorktreeTab({
   onStartDevServer,
   onStopDevServer,
   onOpenDevServerUrl,
+  onViewDevServerLogs,
   onRunInitScript,
   hasInitScript,
 }: WorktreeTabProps) {
@@ -346,6 +348,7 @@ export function WorktreeTab({
         onStartDevServer={onStartDevServer}
         onStopDevServer={onStopDevServer}
         onOpenDevServerUrl={onOpenDevServerUrl}
+        onViewDevServerLogs={onViewDevServerLogs}
         onRunInitScript={onRunInitScript}
         hasInitScript={hasInitScript}
       />

apps/ui/src/components/views/board-view/worktree-panel/hooks/index.ts

@@ -1,5 +1,6 @@
 export { useWorktrees } from './use-worktrees';
 export { useDevServers } from './use-dev-servers';
+export { useDevServerLogs } from './use-dev-server-logs';
 export { useBranches } from './use-branches';
 export { useWorktreeActions } from './use-worktree-actions';
 export { useRunningFeatures } from './use-running-features';

apps/ui/src/components/views/board-view/worktree-panel/hooks/use-dev-server-logs.ts

@@ -0,0 +1,221 @@
+import { useState, useEffect, useCallback, useRef } from 'react';
+import { createLogger } from '@automaker/utils/logger';
+import { getElectronAPI } from '@/lib/electron';
+import { pathsEqual } from '@/lib/utils';
+
+const logger = createLogger('DevServerLogs');
+
+export interface DevServerLogState {
+  /** The log content (buffered + live) */
+  logs: string;
+  /** Whether the server is currently running */
+  isRunning: boolean;
+  /** Whether initial logs are being fetched */
+  isLoading: boolean;
+  /** Error message if fetching logs failed */
+  error: string | null;
+  /** Server port (if running) */
+  port: number | null;
+  /** Server URL (if running) */
+  url: string | null;
+  /** Timestamp when the server started */
+  startedAt: string | null;
+  /** Exit code (if server stopped) */
+  exitCode: number | null;
+  /** Error message from server (if stopped with error) */
+  serverError: string | null;
+}
+
+interface UseDevServerLogsOptions {
+  /** Path to the worktree to monitor logs for */
+  worktreePath: string | null;
+  /** Whether to automatically subscribe to log events (default: true) */
+  autoSubscribe?: boolean;
+}
+
+/**
+ * Hook to subscribe to dev server log events and manage log state.
+ *
+ * This hook:
+ * 1. Fetches initial buffered logs from the server
+ * 2. Subscribes to WebSocket events for real-time log streaming
+ * 3. Handles server started/stopped events
+ * 4. Provides log state for rendering in a panel
+ *
+ * @example
+ * ```tsx
+ * const { logs, isRunning, isLoading } = useDevServerLogs({
+ *   worktreePath: '/path/to/worktree'
+ * });
+ * ```
+ */
+export function useDevServerLogs({ worktreePath, autoSubscribe = true }: UseDevServerLogsOptions) {
+  const [state, setState] = useState<DevServerLogState>({
+    logs: '',
+    isRunning: false,
+    isLoading: false,
+    error: null,
+    port: null,
+    url: null,
+    startedAt: null,
+    exitCode: null,
+    serverError: null,
+  });
+
+  // Keep track of whether we've fetched initial logs
+  const hasFetchedInitialLogs = useRef(false);
+
+  /**
+   * Fetch buffered logs from the server
+   */
+  const fetchLogs = useCallback(async () => {
+    if (!worktreePath) return;
+
+    setState((prev) => ({ ...prev, isLoading: true, error: null }));
+
+    try {
+      const api = getElectronAPI();
+      if (!api?.worktree?.getDevServerLogs) {
+        setState((prev) => ({
+          ...prev,
+          isLoading: false,
+          error: 'Dev server logs API not available',
+        }));
+        return;
+      }
+
+      const result = await api.worktree.getDevServerLogs(worktreePath);
+
+      if (result.success && result.result) {
+        setState((prev) => ({
+          ...prev,
+          logs: result.result!.logs,
+          isRunning: true,
+          isLoading: false,
+          port: result.result!.port,
+          url: `http://localhost:${result.result!.port}`,
+          startedAt: result.result!.startedAt,
+          error: null,
+        }));
+        hasFetchedInitialLogs.current = true;
+      } else {
+        // Server might not be running - this is not necessarily an error
+        setState((prev) => ({
+          ...prev,
+          isLoading: false,
+          isRunning: false,
+          error: result.error || null,
+        }));
+      }
+    } catch (error) {
+      logger.error('Failed to fetch dev server logs:', error);
+      setState((prev) => ({
+        ...prev,
+        isLoading: false,
+        error: error instanceof Error ? error.message : 'Failed to fetch logs',
+      }));
+    }
+  }, [worktreePath]);
+
+  /**
+   * Clear logs and reset state
+   */
+  const clearLogs = useCallback(() => {
+    setState({
+      logs: '',
+      isRunning: false,
+      isLoading: false,
+      error: null,
+      port: null,
+      url: null,
+      startedAt: null,
+      exitCode: null,
+      serverError: null,
+    });
+    hasFetchedInitialLogs.current = false;
+  }, []);
+
+  /**
+   * Append content to logs
+   */
+  const appendLogs = useCallback((content: string) => {
+    setState((prev) => ({
+      ...prev,
+      logs: prev.logs + content,
+    }));
+  }, []);
+
+  // Fetch initial logs when worktreePath changes
+  useEffect(() => {
+    if (worktreePath && autoSubscribe) {
+      hasFetchedInitialLogs.current = false;
+      fetchLogs();
+    } else {
+      clearLogs();
+    }
+  }, [worktreePath, autoSubscribe, fetchLogs, clearLogs]);
+
+  // Subscribe to WebSocket events
+  useEffect(() => {
+    if (!worktreePath || !autoSubscribe) return;
+
+    const api = getElectronAPI();
+    if (!api?.worktree?.onDevServerLogEvent) {
+      logger.warn('Dev server log event API not available');
+      return;
+    }
+
+    const unsubscribe = api.worktree.onDevServerLogEvent((event) => {
+      // Filter events to only handle those for our worktree
+      if (!pathsEqual(event.payload.worktreePath, worktreePath)) return;
+
+      switch (event.type) {
+        case 'dev-server:started': {
+          const { payload } = event;
+          logger.info('Dev server started:', payload);
+          setState((prev) => ({
+            ...prev,
+            isRunning: true,
+            port: payload.port,
+            url: payload.url,
+            startedAt: payload.timestamp,
+            exitCode: null,
+            serverError: null,
+            // Clear logs on restart
+            logs: '',
+          }));
+          hasFetchedInitialLogs.current = false;
+          break;
+        }
+        case 'dev-server:output': {
+          const { payload } = event;
+          // Append the new output to existing logs
+          if (payload.content) {
+            appendLogs(payload.content);
+          }
+          break;
+        }
+        case 'dev-server:stopped': {
+          const { payload } = event;
+          logger.info('Dev server stopped:', payload);
+          setState((prev) => ({
+            ...prev,
+            isRunning: false,
+            exitCode: payload.exitCode,
+            serverError: payload.error ?? null,
+          }));
+          break;
+        }
+      }
+    });
+
+    return unsubscribe;
+  }, [worktreePath, autoSubscribe, appendLogs]);
+
+  return {
+    ...state,
+    fetchLogs,
+    clearLogs,
+    appendLogs,
+  };
+}

apps/ui/src/components/views/board-view/worktree-panel/worktree-panel.tsx

@@ -15,6 +15,7 @@ import {
 } from './hooks';
 import {
   WorktreeTab,
+  DevServerLogsPanel,
   WorktreeMobileDropdown,
   WorktreeActionsDropdown,
   BranchSwitchDropdown,
@@ -90,6 +91,10 @@ export function WorktreePanel({
   // Track whether init script exists for the project
   const [hasInitScript, setHasInitScript] = useState(false);
 
+  // Log panel state management
+  const [logPanelOpen, setLogPanelOpen] = useState(false);
+  const [logPanelWorktree, setLogPanelWorktree] = useState<WorktreeInfo | null>(null);
+
   useEffect(() => {
     if (!projectPath) {
       setHasInitScript(false);
@@ -172,6 +177,18 @@ export function WorktreePanel({
     [projectPath]
   );
 
+  // Handle opening the log panel for a specific worktree
+  const handleViewDevServerLogs = useCallback((worktree: WorktreeInfo) => {
+    setLogPanelWorktree(worktree);
+    setLogPanelOpen(true);
+  }, []);
+
+  // Handle closing the log panel
+  const handleCloseLogPanel = useCallback(() => {
+    setLogPanelOpen(false);
+    // Keep logPanelWorktree set for smooth close animation
+  }, []);
+
   const mainWorktree = worktrees.find((w) => w.isMain);
   const nonMainWorktrees = worktrees.filter((w) => !w.isMain);
 
@@ -320,6 +337,7 @@ export function WorktreePanel({
             onStartDevServer={handleStartDevServer}
             onStopDevServer={handleStopDevServer}
             onOpenDevServerUrl={handleOpenDevServerUrl}
+            onViewDevServerLogs={handleViewDevServerLogs}
             onRunInitScript={handleRunInitScript}
             hasInitScript={hasInitScript}
           />
@@ -376,6 +394,7 @@ export function WorktreePanel({
                   onStartDevServer={handleStartDevServer}
                   onStopDevServer={handleStopDevServer}
                   onOpenDevServerUrl={handleOpenDevServerUrl}
+                  onViewDevServerLogs={handleViewDevServerLogs}
                   onRunInitScript={handleRunInitScript}
                   hasInitScript={hasInitScript}
                 />
@@ -410,6 +429,15 @@ export function WorktreePanel({
           </div>
         </>
       )}
+
+      {/* Dev Server Logs Panel */}
+      <DevServerLogsPanel
+        open={logPanelOpen}
+        onClose={handleCloseLogPanel}
+        worktree={logPanelWorktree}
+        onStopDevServer={handleStopDevServer}
+        onOpenDevServerUrl={handleOpenDevServerUrl}
+      />
     </div>
   );
 }

apps/ui/src/lib/electron.ts

@@ -1774,6 +1774,22 @@ function createMockWorktreeAPI(): WorktreeAPI {
       };
     },
 
+    getDevServerLogs: async (worktreePath: string) => {
+      console.log('[Mock] Getting dev server logs:', { worktreePath });
+      return {
+        success: false,
+        error: 'No dev server running for this worktree',
+      };
+    },
+
+    onDevServerLogEvent: (callback) => {
+      console.log('[Mock] Subscribing to dev server log events');
+      // Return unsubscribe function
+      return () => {
+        console.log('[Mock] Unsubscribing from dev server log events');
+      };
+    },
+
     getPRInfo: async (worktreePath: string, branchName: string) => {
       console.log('[Mock] Getting PR info:', { worktreePath, branchName });
       return {

apps/ui/src/lib/http-api-client.ts

@@ -511,7 +511,53 @@ type EventType =
   | 'ideation:analysis'
   | 'worktree:init-started'
   | 'worktree:init-output'
-  | 'worktree:init-completed';
+  | 'worktree:init-completed'
+  | 'dev-server:started'
+  | 'dev-server:output'
+  | 'dev-server:stopped';
+
+/**
+ * Dev server log event payloads for WebSocket streaming
+ */
+export interface DevServerStartedEvent {
+  worktreePath: string;
+  port: number;
+  url: string;
+  timestamp: string;
+}
+
+export interface DevServerOutputEvent {
+  worktreePath: string;
+  content: string;
+  timestamp: string;
+}
+
+export interface DevServerStoppedEvent {
+  worktreePath: string;
+  port: number;
+  exitCode: number | null;
+  error?: string;
+  timestamp: string;
+}
+
+export type DevServerLogEvent =
+  | { type: 'dev-server:started'; payload: DevServerStartedEvent }
+  | { type: 'dev-server:output'; payload: DevServerOutputEvent }
+  | { type: 'dev-server:stopped'; payload: DevServerStoppedEvent };
+
+/**
+ * Response type for fetching dev server logs
+ */
+export interface DevServerLogsResponse {
+  success: boolean;
+  result?: {
+    worktreePath: string;
+    port: number;
+    logs: string;
+    startedAt: string;
+  };
+  error?: string;
+}
 
 type EventCallback = (payload: unknown) => void;
 
@@ -1714,6 +1760,24 @@ export class HttpApiClient implements ElectronAPI {
       this.post('/api/worktree/start-dev', { projectPath, worktreePath }),
     stopDevServer: (worktreePath: string) => this.post('/api/worktree/stop-dev', { worktreePath }),
     listDevServers: () => this.post('/api/worktree/list-dev-servers', {}),
+    getDevServerLogs: (worktreePath: string): Promise<DevServerLogsResponse> =>
+      this.get(`/api/worktree/dev-server-logs?worktreePath=${encodeURIComponent(worktreePath)}`),
+    onDevServerLogEvent: (callback: (event: DevServerLogEvent) => void) => {
+      const unsub1 = this.subscribeToEvent('dev-server:started', (payload) =>
+        callback({ type: 'dev-server:started', payload: payload as DevServerStartedEvent })
+      );
+      const unsub2 = this.subscribeToEvent('dev-server:output', (payload) =>
+        callback({ type: 'dev-server:output', payload: payload as DevServerOutputEvent })
+      );
+      const unsub3 = this.subscribeToEvent('dev-server:stopped', (payload) =>
+        callback({ type: 'dev-server:stopped', payload: payload as DevServerStoppedEvent })
+      );
+      return () => {
+        unsub1();
+        unsub2();
+        unsub3();
+      };
+    },
     getPRInfo: (worktreePath: string, branchName: string) =>
       this.post('/api/worktree/pr-info', { worktreePath, branchName }),
     // Init script methods

apps/ui/src/types/electron.d.ts

@@ -985,6 +985,43 @@ export interface WorktreeAPI {
     error?: string;
   }>;
 
+  // Get buffered logs for a dev server
+  getDevServerLogs: (worktreePath: string) => Promise<{
+    success: boolean;
+    result?: {
+      worktreePath: string;
+      port: number;
+      logs: string;
+      startedAt: string;
+    };
+    error?: string;
+  }>;
+
+  // Subscribe to dev server log events (started, output, stopped)
+  onDevServerLogEvent: (
+    callback: (
+      event:
+        | {
+            type: 'dev-server:started';
+            payload: { worktreePath: string; port: number; url: string; timestamp: string };
+          }
+        | {
+            type: 'dev-server:output';
+            payload: { worktreePath: string; content: string; timestamp: string };
+          }
+        | {
+            type: 'dev-server:stopped';
+            payload: {
+              worktreePath: string;
+              port: number;
+              exitCode: number | null;
+              error?: string;
+              timestamp: string;
+            };
+          }
+    ) => void
+  ) => () => void;
+
   // Get PR info and comments for a branch
   getPRInfo: (
     worktreePath: string,

libs/types/src/event.ts

@@ -42,6 +42,9 @@ export type EventType =
   | 'ideation:idea-converted'
   | 'worktree:init-started'
   | 'worktree:init-output'
-  | 'worktree:init-completed';
+  | 'worktree:init-completed'
+  | 'dev-server:started'
+  | 'dev-server:output'
+  | 'dev-server:stopped';
 
 export type EventCallback = (type: EventType, payload: unknown) => void;